5da127bbe1f27ea8ca9b824f29348e5d3503ab39
[safe/jmp/linux-2.6] / drivers / regulator / ab3100.c
1 /*
2  * drivers/regulator/ab3100.c
3  *
4  * Copyright (C) 2008-2009 ST-Ericsson AB
5  * License terms: GNU General Public License (GPL) version 2
6  * Low-level control of the AB3100 IC Low Dropout (LDO)
7  * regulators, external regulator and buck converter
8  * Author: Mattias Wallin <mattias.wallin@stericsson.com>
9  * Author: Linus Walleij <linus.walleij@stericsson.com>
10  */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/err.h>
16 #include <linux/delay.h>
17 #include <linux/platform_device.h>
18 #include <linux/regulator/driver.h>
19 #include <linux/mfd/ab3100.h>
20
21 /* LDO registers and some handy masking definitions for AB3100 */
22 #define AB3100_LDO_A            0x40
23 #define AB3100_LDO_C            0x41
24 #define AB3100_LDO_D            0x42
25 #define AB3100_LDO_E            0x43
26 #define AB3100_LDO_E_SLEEP      0x44
27 #define AB3100_LDO_F            0x45
28 #define AB3100_LDO_G            0x46
29 #define AB3100_LDO_H            0x47
30 #define AB3100_LDO_H_SLEEP_MODE 0
31 #define AB3100_LDO_H_SLEEP_EN   2
32 #define AB3100_LDO_ON           4
33 #define AB3100_LDO_H_VSEL_AC    5
34 #define AB3100_LDO_K            0x48
35 #define AB3100_LDO_EXT          0x49
36 #define AB3100_BUCK             0x4A
37 #define AB3100_BUCK_SLEEP       0x4B
38 #define AB3100_REG_ON_MASK      0x10
39
40 /**
41  * struct ab3100_regulator
42  * A struct passed around the individual regulator functions
43  * @platform_device: platform device holding this regulator
44  * @ab3100: handle to the AB3100 parent chip
45  * @plfdata: AB3100 platform data passed in at probe time
46  * @regreg: regulator register number in the AB3100
47  * @fixed_voltage: a fixed voltage for this regulator, if this
48  *          0 the voltages array is used instead.
49  * @typ_voltages: an array of available typical voltages for
50  *          this regulator
51  * @voltages_len: length of the array of available voltages
52  */
53 struct ab3100_regulator {
54         struct regulator_dev *rdev;
55         struct ab3100 *ab3100;
56         struct ab3100_platform_data *plfdata;
57         u8 regreg;
58         int fixed_voltage;
59         int const *typ_voltages;
60         u8 voltages_len;
61 };
62
63 /* The order in which registers are initialized */
64 static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
65         AB3100_LDO_A,
66         AB3100_LDO_C,
67         AB3100_LDO_E,
68         AB3100_LDO_E_SLEEP,
69         AB3100_LDO_F,
70         AB3100_LDO_G,
71         AB3100_LDO_H,
72         AB3100_LDO_K,
73         AB3100_LDO_EXT,
74         AB3100_BUCK,
75         AB3100_BUCK_SLEEP,
76         AB3100_LDO_D,
77 };
78
79 /* Preset (hardware defined) voltages for these regulators */
80 #define LDO_A_VOLTAGE 2750000
81 #define LDO_C_VOLTAGE 2650000
82 #define LDO_D_VOLTAGE 2650000
83
84 static const int ldo_e_buck_typ_voltages[] = {
85         1800000,
86         1400000,
87         1300000,
88         1200000,
89         1100000,
90         1050000,
91         900000,
92 };
93
94 static const int ldo_f_typ_voltages[] = {
95         1800000,
96         1400000,
97         1300000,
98         1200000,
99         1100000,
100         1050000,
101         2500000,
102         2650000,
103 };
104
105 static const int ldo_g_typ_voltages[] = {
106         2850000,
107         2750000,
108         1800000,
109         1500000,
110 };
111
112 static const int ldo_h_typ_voltages[] = {
113         2750000,
114         1800000,
115         1500000,
116         1200000,
117 };
118
119 static const int ldo_k_typ_voltages[] = {
120         2750000,
121         1800000,
122 };
123
124
125 /* The regulator devices */
126 static struct ab3100_regulator
127 ab3100_regulators[AB3100_NUM_REGULATORS] = {
128         {
129                 .regreg = AB3100_LDO_A,
130                 .fixed_voltage = LDO_A_VOLTAGE,
131         },
132         {
133                 .regreg = AB3100_LDO_C,
134                 .fixed_voltage = LDO_C_VOLTAGE,
135         },
136         {
137                 .regreg = AB3100_LDO_D,
138                 .fixed_voltage = LDO_D_VOLTAGE,
139         },
140         {
141                 .regreg = AB3100_LDO_E,
142                 .typ_voltages = ldo_e_buck_typ_voltages,
143                 .voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
144         },
145         {
146                 .regreg = AB3100_LDO_F,
147                 .typ_voltages = ldo_f_typ_voltages,
148                 .voltages_len = ARRAY_SIZE(ldo_f_typ_voltages),
149         },
150         {
151                 .regreg = AB3100_LDO_G,
152                 .typ_voltages = ldo_g_typ_voltages,
153                 .voltages_len = ARRAY_SIZE(ldo_g_typ_voltages),
154         },
155         {
156                 .regreg = AB3100_LDO_H,
157                 .typ_voltages = ldo_h_typ_voltages,
158                 .voltages_len = ARRAY_SIZE(ldo_h_typ_voltages),
159         },
160         {
161                 .regreg = AB3100_LDO_K,
162                 .typ_voltages = ldo_k_typ_voltages,
163                 .voltages_len = ARRAY_SIZE(ldo_k_typ_voltages),
164         },
165         {
166                 .regreg = AB3100_LDO_EXT,
167                 /* No voltages for the external regulator */
168         },
169         {
170                 .regreg = AB3100_BUCK,
171                 .typ_voltages = ldo_e_buck_typ_voltages,
172                 .voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
173         },
174 };
175
176 /*
177  * General functions for enable, disable and is_enabled used for
178  * LDO: A,C,E,F,G,H,K,EXT and BUCK
179  */
180 static int ab3100_enable_regulator(struct regulator_dev *reg)
181 {
182         struct ab3100_regulator *abreg = reg->reg_data;
183         int err;
184         u8 regval;
185
186         err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
187                                                 &regval);
188         if (err) {
189                 dev_warn(&reg->dev, "failed to get regid %d value\n",
190                          abreg->regreg);
191                 return err;
192         }
193
194         /* The regulator is already on, no reason to go further */
195         if (regval & AB3100_REG_ON_MASK)
196                 return 0;
197
198         regval |= AB3100_REG_ON_MASK;
199
200         err = ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
201                                                 regval);
202         if (err) {
203                 dev_warn(&reg->dev, "failed to set regid %d value\n",
204                          abreg->regreg);
205                 return err;
206         }
207
208         /* Per-regulator power on delay from spec */
209         switch (abreg->regreg) {
210         case AB3100_LDO_A: /* Fallthrough */
211         case AB3100_LDO_C: /* Fallthrough */
212         case AB3100_LDO_D: /* Fallthrough */
213         case AB3100_LDO_E: /* Fallthrough */
214         case AB3100_LDO_H: /* Fallthrough */
215         case AB3100_LDO_K:
216                 udelay(200);
217                 break;
218         case AB3100_LDO_F:
219                 udelay(600);
220                 break;
221         case AB3100_LDO_G:
222                 udelay(400);
223                 break;
224         case AB3100_BUCK:
225                 mdelay(1);
226                 break;
227         default:
228                 break;
229         }
230
231         return 0;
232 }
233
234 static int ab3100_disable_regulator(struct regulator_dev *reg)
235 {
236         struct ab3100_regulator *abreg = reg->reg_data;
237         int err;
238         u8 regval;
239
240         /*
241          * LDO D is a special regulator. When it is disabled, the entire
242          * system is shut down. So this is handled specially.
243          */
244         if (abreg->regreg == AB3100_LDO_D) {
245                 int i;
246
247                 dev_info(&reg->dev, "disabling LDO D - shut down system\n");
248                 /*
249                  * Set regulators to default values, ignore any errors,
250                  * we're going DOWN
251                  */
252                 for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
253                         (void) ab3100_set_register_interruptible(abreg->ab3100,
254                                         ab3100_reg_init_order[i],
255                                         abreg->plfdata->reg_initvals[i]);
256                 }
257
258                 /* Setting LDO D to 0x00 cuts the power to the SoC */
259                 return ab3100_set_register_interruptible(abreg->ab3100,
260                                                          AB3100_LDO_D, 0x00U);
261
262         }
263
264         /*
265          * All other regulators are handled here
266          */
267         err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
268                                                 &regval);
269         if (err) {
270                 dev_err(&reg->dev, "unable to get register 0x%x\n",
271                         abreg->regreg);
272                 return err;
273         }
274         regval &= ~AB3100_REG_ON_MASK;
275         return ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
276                                                  regval);
277 }
278
279 static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
280 {
281         struct ab3100_regulator *abreg = reg->reg_data;
282         u8 regval;
283         int err;
284
285         err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
286                                                 &regval);
287         if (err) {
288                 dev_err(&reg->dev, "unable to get register 0x%x\n",
289                         abreg->regreg);
290                 return err;
291         }
292
293         return regval & AB3100_REG_ON_MASK;
294 }
295
296 static int ab3100_list_voltage_regulator(struct regulator_dev *reg,
297                                          unsigned selector)
298 {
299         struct ab3100_regulator *abreg = reg->reg_data;
300
301         if (selector > abreg->voltages_len)
302                 return -EINVAL;
303         return abreg->typ_voltages[selector];
304 }
305
306 static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
307 {
308         struct ab3100_regulator *abreg = reg->reg_data;
309         u8 regval;
310         int err;
311
312         /* Return the voltage for fixed regulators immediately */
313         if (abreg->fixed_voltage)
314                 return abreg->fixed_voltage;
315
316         /*
317          * For variable types, read out setting and index into
318          * supplied voltage list.
319          */
320         err = ab3100_get_register_interruptible(abreg->ab3100,
321                                                 abreg->regreg, &regval);
322         if (err) {
323                 dev_warn(&reg->dev,
324                          "failed to get regulator value in register %02x\n",
325                          abreg->regreg);
326                 return err;
327         }
328
329         /* The 3 highest bits index voltages */
330         regval &= 0xE0;
331         regval >>= 5;
332
333         if (regval > abreg->voltages_len) {
334                 dev_err(&reg->dev,
335                         "regulator register %02x contains an illegal voltage setting\n",
336                         abreg->regreg);
337                 return -EINVAL;
338         }
339
340         return abreg->typ_voltages[regval];
341 }
342
343 static int ab3100_get_best_voltage_index(struct regulator_dev *reg,
344                                    int min_uV, int max_uV)
345 {
346         struct ab3100_regulator *abreg = reg->reg_data;
347         int i;
348         int bestmatch;
349         int bestindex;
350
351         /*
352          * Locate the minimum voltage fitting the criteria on
353          * this regulator. The switchable voltages are not
354          * in strict falling order so we need to check them
355          * all for the best match.
356          */
357         bestmatch = INT_MAX;
358         bestindex = -1;
359         for (i = 0; i < abreg->voltages_len; i++) {
360                 if (abreg->typ_voltages[i] <= max_uV &&
361                     abreg->typ_voltages[i] >= min_uV &&
362                     abreg->typ_voltages[i] < bestmatch) {
363                         bestmatch = abreg->typ_voltages[i];
364                         bestindex = i;
365                 }
366         }
367
368         if (bestindex < 0) {
369                 dev_warn(&reg->dev, "requested %d<=x<=%d uV, out of range!\n",
370                          min_uV, max_uV);
371                 return -EINVAL;
372         }
373         return bestindex;
374 }
375
376 static int ab3100_set_voltage_regulator(struct regulator_dev *reg,
377                                         int min_uV, int max_uV)
378 {
379         struct ab3100_regulator *abreg = reg->reg_data;
380         u8 regval;
381         int err;
382         int bestindex;
383
384         bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV);
385         if (bestindex < 0)
386                 return bestindex;
387
388         err = ab3100_get_register_interruptible(abreg->ab3100,
389                                                 abreg->regreg, &regval);
390         if (err) {
391                 dev_warn(&reg->dev,
392                          "failed to get regulator register %02x\n",
393                          abreg->regreg);
394                 return err;
395         }
396
397         /* The highest three bits control the variable regulators */
398         regval &= ~0xE0;
399         regval |= (bestindex << 5);
400
401         err = ab3100_set_register_interruptible(abreg->ab3100,
402                                                 abreg->regreg, regval);
403         if (err)
404                 dev_warn(&reg->dev, "failed to set regulator register %02x\n",
405                         abreg->regreg);
406
407         return err;
408 }
409
410 static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
411                                                 int uV)
412 {
413         struct ab3100_regulator *abreg = reg->reg_data;
414         u8 regval;
415         int err;
416         int bestindex;
417         u8 targetreg;
418
419         if (abreg->regreg == AB3100_LDO_E)
420                 targetreg = AB3100_LDO_E_SLEEP;
421         else if (abreg->regreg == AB3100_BUCK)
422                 targetreg = AB3100_BUCK_SLEEP;
423         else
424                 return -EINVAL;
425
426         /* LDO E and BUCK have special suspend voltages you can set */
427         bestindex = ab3100_get_best_voltage_index(reg, uV, uV);
428
429         err = ab3100_get_register_interruptible(abreg->ab3100,
430                                                 targetreg, &regval);
431         if (err) {
432                 dev_warn(&reg->dev,
433                          "failed to get regulator register %02x\n",
434                          targetreg);
435                 return err;
436         }
437
438         /* The highest three bits control the variable regulators */
439         regval &= ~0xE0;
440         regval |= (bestindex << 5);
441
442         err = ab3100_set_register_interruptible(abreg->ab3100,
443                                                 targetreg, regval);
444         if (err)
445                 dev_warn(&reg->dev, "failed to set regulator register %02x\n",
446                         abreg->regreg);
447
448         return err;
449 }
450
451 /*
452  * The external regulator can just define a fixed voltage.
453  */
454 static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
455 {
456         struct ab3100_regulator *abreg = reg->reg_data;
457
458         return abreg->plfdata->external_voltage;
459 }
460
461 static struct regulator_ops regulator_ops_fixed = {
462         .enable      = ab3100_enable_regulator,
463         .disable     = ab3100_disable_regulator,
464         .is_enabled  = ab3100_is_enabled_regulator,
465         .get_voltage = ab3100_get_voltage_regulator,
466 };
467
468 static struct regulator_ops regulator_ops_variable = {
469         .enable      = ab3100_enable_regulator,
470         .disable     = ab3100_disable_regulator,
471         .is_enabled  = ab3100_is_enabled_regulator,
472         .get_voltage = ab3100_get_voltage_regulator,
473         .set_voltage = ab3100_set_voltage_regulator,
474         .list_voltage = ab3100_list_voltage_regulator,
475 };
476
477 static struct regulator_ops regulator_ops_variable_sleepable = {
478         .enable      = ab3100_enable_regulator,
479         .disable     = ab3100_disable_regulator,
480         .is_enabled  = ab3100_is_enabled_regulator,
481         .get_voltage = ab3100_get_voltage_regulator,
482         .set_voltage = ab3100_set_voltage_regulator,
483         .set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
484         .list_voltage = ab3100_list_voltage_regulator,
485 };
486
487 /*
488  * LDO EXT is an external regulator so it is really
489  * not possible to set any voltage locally here, AB3100
490  * is an on/off switch plain an simple. The external
491  * voltage is defined in the board set-up if any.
492  */
493 static struct regulator_ops regulator_ops_external = {
494         .enable      = ab3100_enable_regulator,
495         .disable     = ab3100_disable_regulator,
496         .is_enabled  = ab3100_is_enabled_regulator,
497         .get_voltage = ab3100_get_voltage_regulator_external,
498 };
499
500 static struct regulator_desc
501 ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
502         {
503                 .name = "LDO_A",
504                 .id   = AB3100_LDO_A,
505                 .ops  = &regulator_ops_fixed,
506                 .type = REGULATOR_VOLTAGE,
507         },
508         {
509                 .name = "LDO_C",
510                 .id   = AB3100_LDO_C,
511                 .ops  = &regulator_ops_fixed,
512                 .type = REGULATOR_VOLTAGE,
513         },
514         {
515                 .name = "LDO_D",
516                 .id   = AB3100_LDO_D,
517                 .ops  = &regulator_ops_fixed,
518                 .type = REGULATOR_VOLTAGE,
519         },
520         {
521                 .name = "LDO_E",
522                 .id   = AB3100_LDO_E,
523                 .ops  = &regulator_ops_variable_sleepable,
524                 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
525                 .type = REGULATOR_VOLTAGE,
526         },
527         {
528                 .name = "LDO_F",
529                 .id   = AB3100_LDO_F,
530                 .ops  = &regulator_ops_variable,
531                 .n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
532                 .type = REGULATOR_VOLTAGE,
533         },
534         {
535                 .name = "LDO_G",
536                 .id   = AB3100_LDO_G,
537                 .ops  = &regulator_ops_variable,
538                 .n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
539                 .type = REGULATOR_VOLTAGE,
540         },
541         {
542                 .name = "LDO_H",
543                 .id   = AB3100_LDO_H,
544                 .ops  = &regulator_ops_variable,
545                 .n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
546                 .type = REGULATOR_VOLTAGE,
547         },
548         {
549                 .name = "LDO_K",
550                 .id   = AB3100_LDO_K,
551                 .ops  = &regulator_ops_variable,
552                 .n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
553                 .type = REGULATOR_VOLTAGE,
554         },
555         {
556                 .name = "LDO_EXT",
557                 .id   = AB3100_LDO_EXT,
558                 .ops  = &regulator_ops_external,
559                 .type = REGULATOR_VOLTAGE,
560         },
561         {
562                 .name = "BUCK",
563                 .id   = AB3100_BUCK,
564                 .ops  = &regulator_ops_variable_sleepable,
565                 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
566                 .type = REGULATOR_VOLTAGE,
567         },
568 };
569
570 /*
571  * NOTE: the following functions are regulators pluralis - it is the
572  * binding to the AB3100 core driver and the parent platform device
573  * for all the different regulators.
574  */
575
576 static int __init ab3100_regulators_probe(struct platform_device *pdev)
577 {
578         struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
579         struct ab3100 *ab3100 = platform_get_drvdata(pdev);
580         int err = 0;
581         u8 data;
582         int i;
583
584         /* Check chip state */
585         err = ab3100_get_register_interruptible(ab3100,
586                                                 AB3100_LDO_D, &data);
587         if (err) {
588                 dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
589                 return err;
590         }
591         if (data & 0x10)
592                 dev_notice(&pdev->dev,
593                            "chip is already in active mode (Warm start)\n");
594         else
595                 dev_notice(&pdev->dev,
596                            "chip is in inactive mode (Cold start)\n");
597
598         /* Set up regulators */
599         for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
600                 err = ab3100_set_register_interruptible(ab3100,
601                                         ab3100_reg_init_order[i],
602                                         plfdata->reg_initvals[i]);
603                 if (err) {
604                         dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
605                                 err);
606                         return err;
607                 }
608         }
609
610         if (err) {
611                 dev_err(&pdev->dev,
612                         "LDO D regulator initialization failed with error %d\n",
613                         err);
614                 return err;
615         }
616
617         /* Register the regulators */
618         for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
619                 struct ab3100_regulator *reg = &ab3100_regulators[i];
620                 struct regulator_dev *rdev;
621
622                 /*
623                  * Initialize per-regulator struct.
624                  * Inherit platform data, this comes down from the
625                  * i2c boarddata, from the machine. So if you want to
626                  * see what it looks like for a certain machine, go
627                  * into the machine I2C setup.
628                  */
629                 reg->ab3100 = ab3100;
630                 reg->plfdata = plfdata;
631
632                 /*
633                  * Register the regulator, pass around
634                  * the ab3100_regulator struct
635                  */
636                 rdev = regulator_register(&ab3100_regulator_desc[i],
637                                           &pdev->dev,
638                                           &plfdata->reg_constraints[i],
639                                           reg);
640
641                 if (IS_ERR(rdev)) {
642                         err = PTR_ERR(rdev);
643                         dev_err(&pdev->dev,
644                                 "%s: failed to register regulator %s err %d\n",
645                                 __func__, ab3100_regulator_desc[i].name,
646                                 err);
647                         i--;
648                         /* remove the already registered regulators */
649                         while (i > 0) {
650                                 regulator_unregister(ab3100_regulators[i].rdev);
651                                 i--;
652                         }
653                         return err;
654                 }
655
656                 /* Then set a pointer back to the registered regulator */
657                 reg->rdev = rdev;
658         }
659
660         return 0;
661 }
662
663 static int __exit ab3100_regulators_remove(struct platform_device *pdev)
664 {
665         int i;
666
667         for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
668                 struct ab3100_regulator *reg = &ab3100_regulators[i];
669
670                 regulator_unregister(reg->rdev);
671         }
672         return 0;
673 }
674
675 static struct platform_driver ab3100_regulators_driver = {
676         .driver = {
677                 .name  = "ab3100-regulators",
678                 .owner = THIS_MODULE,
679         },
680         .probe = ab3100_regulators_probe,
681         .remove = __exit_p(ab3100_regulators_remove),
682 };
683
684 static __init int ab3100_regulators_init(void)
685 {
686         return platform_driver_register(&ab3100_regulators_driver);
687 }
688
689 static __exit void ab3100_regulators_exit(void)
690 {
691         platform_driver_register(&ab3100_regulators_driver);
692 }
693
694 subsys_initcall(ab3100_regulators_init);
695 module_exit(ab3100_regulators_exit);
696
697 MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
698 MODULE_DESCRIPTION("AB3100 Regulator driver");
699 MODULE_LICENSE("GPL");
700 MODULE_ALIAS("platform:ab3100-regulators");